Existing High-speed Packet Access (HSPA) systems are borne on a signal frequency point. In order to improve a data transmission rate of the HSPA system and reduce the delay, so as to improve the user experience, a solution of binding a plurality of frequency points to bear HSPA data is proposed. In this solution, two (or more) carrier frequencies of 5 MHz in a downlink (DL) direction are bounded together for transmitting the HSPA data. The most important is to bind the two carrier frequencies, in which the two carrier frequencies may be considered as frequency points respectively used by two cells covering the same area. Furthermore, the number of the carrier frequencies used by uplink (UL) and DL may be the same or different, but generally, the number of the DL carrier frequencies is greater than that of the UL carrier frequencies. In a system for binding a plurality of carrier frequencies for transmitting HSPA data, two carrier frequencies are used for DL, and two carrier frequencies are used for UL, which is so-called a 2*2 mode; or two carrier frequencies are used for DL, and one carrier frequency is used for UL, which is so-called a 2*1 mode. In the two modes, two carrier frequencies are used for DL.
One multi-carrier/cell may support a plurality of carrier frequencies, and the cells corresponding to the carrier frequencies generally have a certain correlation in geographical position. The multi-carrier/cell has two definitions: one refers to a special cell different from the original single carrier/cell, having its own cell ID, supporting a plurality of carrier frequencies; and the other refers to a cell set, in which each cell is an independent individual like the original single carrier/cell, and the cell IDs of the cells may be the same or different.
With the concept of primary carrier frequency introduced, if only one carrier frequency is used by the UL or DL simultaneously, the frequency point serves as a primary carrier frequency. If UL and DL service is borne on a Dedicated Channel (DCH), the frequency point where the DCH is located serves as the primary carrier frequency. If two carrier frequencies are used by the UL and the DL simultaneously, and no service is borne on the DCH, a Radio Network Controller (RNC) determines to change the primary carrier frequency according to the 2a event (preferably, carrier frequency change) reported by a User Equipment (UE). After the primary carrier frequency is changed each time, the RNC delivers a new measurement control message to notify the UE of the frequency points for co-channel switching measurement.
The UE determines to trigger a 1x/2x event only according to the primary carrier frequency. But when the measurement report is reported, only information of the two frequency points needs to be carried. When the network side determines whether to add the cell into an activity set (especially when a 1d event is triggered), the signal quality of the two carrier frequencies should be taken into consideration.
In the foregoing description, the measurement event of the carrier frequency/cell of the non-primary carrier frequency uses a different frequency event, such as, 2x event, and the measurement event of the carrier frequency/cell of the carrier frequency uses a 1x event. For example, the primary carrier frequency is corresponding to a carrier frequency A, and cells 1 and 2; and the non-primary carrier frequency is corresponding to a carrier frequency B, and cells 3 and 4. The measurement event of the cells 3 and 4 uses events 2a, 2b, 2c, 2d, and the measurement event of the cells 1 and 2 uses events 1a, 1b, 1c, 1d. 
In the prior art, a multi-carrier/cell can be used for data transmission, as the environment where the user terminal is located varies at any time, and accordingly, the carrier frequency quality also varies with the environment. However, no method for adjusting the carrier frequency according to the carrier frequency quality is provided, and thus the optimization of the network quality is influenced.